The 46-year-old boxer, famed for winning world titles in four different weight categories, drank tea with Putin in Crimea's naval port city of Sevastopol, photographs released by the Kremlin showed.

Jones, who has branched out into rap and acting in films, was in Crimea to appear at a boxing show August 23.

"I think that if I had a Russian passport...it would be a lot easier for me to come and go, because people love sport here, and so I love this place," Jones told Putin.

Putin replied: "If you intend to link a significant part of your life with activities in Russia, then of course we will be glad and will fulfill your request to receive Russian citizenship with pleasure."

Jones said he hoped sport could help "build a bridge" between the United States and Russia. Tensions have flared to Cold War levels since last year when Russia took possession of Crimea from Ukraine.